Process of purifying hydrogen gas.



two).

unrrm) sTATns PATENT OFFICE.

CARL BOSCH AND WILHELM WILD, 0F LUDWIGSI-IAFEN-ON-THE-RHINE, GERMANY,

ASSIGNORS TO BADISCHE ANILIN & SODA FABRIK, 0F LUDWIGSHAFEN-ON-THE- RHINE, GERMANY, A. CORPORATION.-

PROGESS 0F PUBIFYING HYDROGEN GAS.

No Drawing.

To all whom it may concern:

Be it known that we, CARL Boson and \VILHELM VVILD, subjects, respectively, of the King of Prussia and the Grand Duke of Baden, residing at Ludwigshafen-on-the- Rhine, Germany, have invented new and useful Improvements in the Process of Purifying Hydrogen Gas, of which the following is a specification.

When, in the production of hydrogen, coal or other carbonaceous material is employed either directly or indirectly, the hydrogen obtained always contagmswcarbo m onoxid. As instances of such methods of producing hydrogen, we mention passing steam over highly heated coal or coke, also soaking coal in alkaline solution and then heating the mixture with steam at comparatively low temperatures, further heating coal with water under pressure, and also passing hydrocarbons with steam over nic kglat a temperature of say 1000 01 If considerable quantities of carbon monoxid are present, the greater part can be removed, either by liquefaction or by passing the gases over caustic lime, but some carbon monoxid always remains, so that the hydrogen cannot be used for some purposes and is considerably less advantageous in use than pure hydrogen, such as is produced, for instance, by electrolysis. We have now found that we can, on a technical scale, completely abstract carbon monoxid from hydrogen.gascontaim sohltionsoicausticsalkaliyllder pressure exceedmg a of five atmospheres. We prefer to employ 'fairly lfiglh temperatures, for instance from 200 030 270 0., and the caustic alkali solution can be renewed either periodically' or continuously. It was lmown that a caustic alkali solution is capable of combining with carbon monoxid, but no process has hitherto been known for completely removing the smallest quantities of carbon monoxid, and this is not possible when employing other reagents hitherto in use for the absorption of carbon monoxid, such for instance as caustic lime and cuprous chlorid, even when the latter is employed under pressure as described in German Patent N 0. 35,229.

The process of this invention is of particular importance in connection with the cataqoplel of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

. Washington, I). 0."

Specification of Letters Patent.

Patented Jan. 26, 1915.

Application filed January 30, 1912. Serial No. 674,416.

the present invention can be carried out may yary very considerably and in some cases it is advantageous to employ high pressure, for instance, from 140 to 200 atmospheres or even higher, since then the gases can be passed with much greater rapidity through the caustic alkali solution and yet a complete absorption of the carbon monoxid obtained.

The following examples will serve to illustrate further the nature of our invention, which, however, is not confined to these examples.

Example 1: Wash hydrogen containing about pne per gent, pf carbon monoxid, un defa pressure of 50 atmospheres and at a temperature of 260 0., with an 80% solutionof caustic soda. M

EXample-2-PWash hydrogen containing about one per cent. of carbon monoxid, under a pressure of 200 atmospheres and at a temperature of 240 0., with a 25% solution of caustic soda. In a similar manner hydrogen containing carbon monoxid can be treated with solutions containing less than 25% of caustic soda, for instance from 5% upward.

We claim 1. The process of producing pure hydro- I gen consisting in heating hydrogen contain- 1ng small quantities of carbon monoxid undefnampressureaexceedingl fivoalllllgi'sp lieres 0ARL BOSCH. WILI-IELM WILD.

Witnesses:

A. O. TITTMANN, J. ALEc. LLOYD. 

